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Sulfa drugs allergy refers to the adverse reactions noted in your body following consumption of drugs belonging to the group of sulfonamides. This group of drugs was one of the commonly advised antibiotics.

What is sulfa drugs allergy?

It is still being advised in cases where other groups of antibiotics are considered to be not as potent as this. Some people tend to overreact to the commonly advised dosages of these drugs. This has been attributed to some variation in your body’s defense system or the immune system. You may develop allergic reactions that resemble any other allergy a few minutes or few hours after you consume the drug. Some of the common symptoms include formation of rashes on the skin. Although these drugs generally result in mild reactions, it may at times lead to life threatening situations that need immediate care.

Sulfa drugs allergy is noted to affect about 3% of all people. Although not very common, some people are more prone to be allergic to sulfa drugs. The exact reason for this allergy is not known. People suffering from disorder such as HIV/AIDS are known to at a higher risk of being allergic to sulfa drugs than others.

What are the symptoms of sulfa drug allergy?

Sulfa drug allergy can lead to a number of adverse reactions in your body. The symptoms can range from mild reactions to reversible damage to certain organs such as the kidneys. In rare instances it can lead to life threatening situations that need immediate medical attention.

The commonest symptoms of sulfa drug allergy become evident on your skin a few minutes or a few hours after you take the medication. Appearance of rashes over the skin following the administration of medications commonly indicates that you are allergic to that medication. While it may be of mild variety that subsides after some time, some people may suffer from these rashes for a few days. Other symptoms include: sensitivity to sunlight, vomiting sensations, itchy skin or eyes, swelling of the lips, face or tongue and wheezing.

Some of the symptoms that need immediate medical attention include vomiting, diarrhea, breathlessness, fainting, confusions, rapid pulse or rapid heartbeats. These signs and symptoms may indicate life threatening situations that need to be treated at a hospital.

In some cases, sulfa drug allergy can affect some of the specific organs in our body. Conditions such as hepatitis (inflammation of the liver cells) and kidney failure are noted in some people who are allergic to sulfa drugs. In some cases, one may develop infections of the lung. Worsening of the pre-existing conditions such as asthma has also been noted in some cases. In other cases, sulfa drugs may affect the blood cells such as the white blood cells, red blood cells and the platelets leading to a decrease in their numbers. Such changes in the body may often lead to serious situations that need immediate medical attention.

How do I know that I am allergic to sulfa drugs?

There are no specific tests (such as those for penicillin allergies) that can be used to test whether you are allergic to sulfa drugs or not. It is commonly identified based on the adverse reactions noted following the administration of this drug. You must always note down any adverse reaction noted in your body following the consumption of these drugs and inform a healthcare provider about this when he/she is prescribing you medications. 

How do I prevent sulfa drug allergy?

If you know that you are suffering from sulfa allergy inform your healthcare providers before they:

  • Prescribe any medications
  • Perform or plan for any minor or major surgeries
  • Treat any disorders or conditions

It is also advised that you read through the labels of all the medicines advised for you before consuming them. Call your healthcare provider or your pharmacist at the first instance of any adverse reactions. The earlier you inform, the easier it becomes to treat.

Read More: Allergic to Anticonvulsants: Anticonvulsant Allergy Side Effects

How do I deal with sulfa drug allergy?

One of the easiest ways to treat sulfa drug allergy in mild cases is stopping the consumption of the sulfa drugs. Inform your healthcare provider about the adverse reactions that you noted, so that he/she can change the type of antibiotic advised for you. In case of moderate to severe reactions you need to visit to the hospital for further care. Your doctor may prescribe you other medications to counter the allergic reaction and reduce the symptoms of allergy. In some cases you may need to be admitted at the hospital.

The best way to deal with sulfa drug allergy is to prevent its occurrence. There are several medications that belong to the group of sulfa drugs. Some of these drugs have been mentioned in detail below. Make sure to read the label of any drug before you start taking them.

  • Sulfonamide antibiotics such as trimethoprim-sulfamethoxazole (common drugs include Septra®, Bactrim® and others), sulfisoxazole, sulfadizine, and dapsone.
  • Topical preparations (to be applied on the skin) such as sulfacetamide eye drops, shampoo or creams, silver sulfadiazine cream/ointment, and sulfanilamide containing vaginal creams/lotions.
  • Sulfasalazine (Azulfidine) a drug used to treat conditions such as Crohn's disease, ulcerative colitis and rheumatoid arthritis.
  • Some of the diuretic medications that are commonly advised in patients with high blood pressure may cause allergic reactions in people allergic to sulfa drugs. Inform your doctor if you are suffering from sulfa allergy and need to take diuretics.
  • Dapsone, a medication advised to treat conditions such as leprosy, skin inflammation and certain types of pneumonia.
  • Diabetic medications that belong to the group of sulfonylureas may cause adverse reactions in people allergic to sulfa drugs. So if you are allergic to sulfa drugs and suffer from diabetes, inform your doctor beforehand about your allergy.
  • Pain medications such as celecoxib (Celebrex) and migraine medicines such as sumatriptan (Imitrex) are may be associated with adverse reactions in people allergic to sulfa drugs.